[PATCH 5.4 only] powerpc: boot: Remove unnecessary zero in label in udelay()

[PATCH 5.4 only] powerpc: boot: Remove unnecessary zero in label in udelay()

[Nathan Chancellor]

When building powerpc configurations in linux-5.4.y with binutils 2.43
or newer, there is an assembler error in arch/powerpc/boot/util.S:

  arch/powerpc/boot/util.S: Assembler messages:
  arch/powerpc/boot/util.S:44: Error: junk at end of line, first unrecognized character is `0'
  arch/powerpc/boot/util.S:49: Error: syntax error; found `b', expected `,'
  arch/powerpc/boot/util.S:49: Error: junk at end of line: `b'

binutils 2.43 contains stricter parsing of certain labels [1].

Remove the unnecessary leading zero to fix the build. This is only
needed in linux-5.4.y because commit 8b14e1dff067 ("powerpc: Remove
support for PowerPC 601") removed this code altogether in 5.10.

Link: https://sourceware.org/git/?p=binutils-gdb.git;a=commit;h=226749d5a6ff0d5c607d6428d6c81e1e7e7a994b [1]
Signed-off-by: Nathan Chancellor <nathan@kernel.org>
---
 arch/powerpc/boot/util.S | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/arch/powerpc/boot/util.S b/arch/powerpc/boot/util.S
index f11f0589a669..5ab2bc864e66 100644
--- a/arch/powerpc/boot/util.S
+++ b/arch/powerpc/boot/util.S
@@ -41,12 +41,12 @@ udelay:
 	srwi	r4,r4,16
 	cmpwi	0,r4,1		/* 601 ? */
 	bne	.Ludelay_not_601
-00:	li	r0,86	/* Instructions / microsecond? */
+0:	li	r0,86	/* Instructions / microsecond? */
 	mtctr	r0
 10:	addi	r0,r0,0 /* NOP */
 	bdnz	10b
 	subic.	r3,r3,1
-	bne	00b
+	bne	0b
 	blr
 
 .Ludelay_not_601:

base-commit: c25f780e491e4734eb27d65aa58e0909fd78ad9f
-- 
2.51.0

Re: [PATCH 5.4 only] powerpc: boot: Remove unnecessary zero in label in udelay()

[kernel test robot]

Hi,

Thanks for your patch.

FYI: kernel test robot notices the stable kernel rule is not satisfied.

The check is based on https://www.kernel.org/doc/html/latest/process/stable-kernel-rules.html#option-3

Rule: The upstream commit ID must be specified with a separate line above the commit text.
Subject: [PATCH 5.4 only] powerpc: boot: Remove unnecessary zero in label in udelay()
Link: https://lore.kernel.org/stable/20250902235234.2046667-1-nathan%40kernel.org

Please ignore this mail if the patch is not relevant for upstream.

-- 
0-DAY CI Kernel Test Service
https://github.com/intel/lkp-tests/wiki

Re: [PATCH 5.4 only] powerpc: boot: Remove unnecessary zero in label in udelay()

[Segher Boessenkool]

Hi!

On Tue, Sep 02, 2025 at 04:52:34PM -0700, Nathan Chancellor wrote:
> When building powerpc configurations in linux-5.4.y with binutils 2.43
> or newer, there is an assembler error in arch/powerpc/boot/util.S:
> 
>   arch/powerpc/boot/util.S: Assembler messages:
>   arch/powerpc/boot/util.S:44: Error: junk at end of line, first unrecognized character is `0'
>   arch/powerpc/boot/util.S:49: Error: syntax error; found `b', expected `,'
>   arch/powerpc/boot/util.S:49: Error: junk at end of line: `b'
> 
> binutils 2.43 contains stricter parsing of certain labels [1].
> 
> Remove the unnecessary leading zero to fix the build.

To fix it by getting rid of this syntax error, you mean?  "00" is not a
valid label name: a) it cannot be a symbol name, it starts with a digit;
and b) it isn't a valid local label either.  As the manual says
> To define a local label, write a label of the form ‘N:’ (where N
> represents any non-negative integer).
"0" is written "0", not as "00" (or "0-0" or even "0-0-0", hehe).


Segher

Re: [PATCH 5.4 only] powerpc: boot: Remove unnecessary zero in label in udelay()

[Nathan Chancellor]

On Wed, Sep 03, 2025 at 01:15:38AM -0500, Segher Boessenkool wrote:
> Hi!
> 
> On Tue, Sep 02, 2025 at 04:52:34PM -0700, Nathan Chancellor wrote:
> > When building powerpc configurations in linux-5.4.y with binutils 2.43
> > or newer, there is an assembler error in arch/powerpc/boot/util.S:
> > 
> >   arch/powerpc/boot/util.S: Assembler messages:
> >   arch/powerpc/boot/util.S:44: Error: junk at end of line, first unrecognized character is `0'
> >   arch/powerpc/boot/util.S:49: Error: syntax error; found `b', expected `,'
> >   arch/powerpc/boot/util.S:49: Error: junk at end of line: `b'
> > 
> > binutils 2.43 contains stricter parsing of certain labels [1].
> > 
> > Remove the unnecessary leading zero to fix the build.
> 
> To fix it by getting rid of this syntax error, you mean?  "00" is not a
> valid label name: a) it cannot be a symbol name, it starts with a digit;
> and b) it isn't a valid local label either.  As the manual says
> > To define a local label, write a label of the form ‘N:’ (where N
> > represents any non-negative integer).
> "0" is written "0", not as "00" (or "0-0" or even "0-0-0", hehe).

Sure, I have sent a v2 that hopefully makes it a little clearer that the
code in the kernel was already problematic under the existing rules.

https://lore.kernel.org/20250903211158.2844032-1-nathan@kernel.org/

Cheers,
Nathan

Re: [PATCH 5.4 only] powerpc: boot: Remove unnecessary zero in label in udelay()

[Segher Boessenkool]

Hi!

On Wed, Sep 03, 2025 at 02:14:42PM -0700, Nathan Chancellor wrote:
> On Wed, Sep 03, 2025 at 01:15:38AM -0500, Segher Boessenkool wrote:
> > On Tue, Sep 02, 2025 at 04:52:34PM -0700, Nathan Chancellor wrote:
> > > When building powerpc configurations in linux-5.4.y with binutils 2.43
> > > or newer, there is an assembler error in arch/powerpc/boot/util.S:
> > > 
> > >   arch/powerpc/boot/util.S: Assembler messages:
> > >   arch/powerpc/boot/util.S:44: Error: junk at end of line, first unrecognized character is `0'
> > >   arch/powerpc/boot/util.S:49: Error: syntax error; found `b', expected `,'
> > >   arch/powerpc/boot/util.S:49: Error: junk at end of line: `b'
> > > 
> > > binutils 2.43 contains stricter parsing of certain labels [1].
> > > 
> > > Remove the unnecessary leading zero to fix the build.
> > 
> > To fix it by getting rid of this syntax error, you mean?  "00" is not a
> > valid label name: a) it cannot be a symbol name, it starts with a digit;
> > and b) it isn't a valid local label either.  As the manual says
> > > To define a local label, write a label of the form ‘N:’ (where N
> > > represents any non-negative integer).
> > "0" is written "0", not as "00" (or "0-0" or even "0-0-0", hehe).
> 
> Sure, I have sent a v2 that hopefully makes it a little clearer that the
> code in the kernel was already problematic under the existing rules.
> 
> https://lore.kernel.org/20250903211158.2844032-1-nathan@kernel.org/

You forgot to cc: me on that :-)  I have it via linuxppc-dev@ of course.

Looks great, thank you!


Segher